It is generally understood that there is a strong correlation between increased lateral length and increased initial production rates in a horizontal well. Accordingly, the development of horizontal well drilling in shale formations has pushed lateral lengths of horizontal wellbores to exceed 10,000 feet, with total measured distances of 20,000 feet.
Limiting factors in drilling lateral sections of horizontal wellbores to even greater distances include rotating and sliding frictional forces between the wellbore and the drilling string, namely resistive torque exerted on the outer surface of the drilling string and hole drag, both due to the drilling bottom hole assembly (BHA) and drill pipe contacting the interior surfaces of the wellbore. While the drill pipe and BHA are rotating to advance the wellbore by drilling, the effect of the rotating and sliding friction is reduced; however, when the wellbore direction needs to be adjusted, the drill pipe and BHA must “slide”, no longer rotating while only the drill bit turns. Since there is little or no rotational movement in the drilling string or BHA during the slide, friction may cause difficulty in advancing the bit.
To address such problems, an impulse or vibration tool can be introduced into the drilling string to impart a vibratory motion to the string and potentially the BHA. The inclusion of such prior art tools, however, can create additional challenges while drilling.